Yarn twisting apparatus



Sept- 10, 1963 o. MEILI ErAL YARN TWISTING APPARATUS Filed NOV. 9, 19602 d 2 m. w. m H M 1.... N C Thr P. wlw m 40,687 WMEP m H [m3 o p 7m l TE a u Aww Y di JY M B m/m m -l l .y 7 2V, ik M 2J( W www M M 66m967@will United States Patent O 3,103,097 YARN TWISTING APPARATUS OttoMelli, Wattwil, and `oseph Raschle, Butschwil, Switzerland, assignors toHeberlein Patent Corporation, New York, N.Y., a corporation of New YorkFiled Nov. 9, 1960, Ser. No. 68,235 Claims priority, applicationSwitzerland Nov. 28, 1959 9 Claims. (Cl. 57--77.4)

This invention is directed to apparatus for twisting textile yarns, andmore particularly it relates to an apparatus for false twisting such ayarn.

There are many Well known processes and apparatus for crimping textileyarns, more especially for imparting a high twist to the yarn, in whichstate it is thermally set and subsequently detwisted. The twistingapparatus is designated a false twister since it twists and untwists theyarn, and generally consists of a tube or hollow spindle which isrotated at high `speed by means of a belt drive or by an individualdrive motor. The rotary tube is provided with pins, projections,rollers, or the like which are so arranged that they force the yarnwhich passes longitudinally through the tube to rotate also. In such adevice employing a twisting -tube or spindle the speed of rotation whichcan be imparted to the yarn is directly related to the speed which canhe imparted to the tube, which in turn is a function of the manner inwhich the tube is supported in the overall apparatus.

In order to overcome limitation upon the speed of rotation which isimposed by the bearings supporting the twisting tube, methods andapparatus have been devised whereby twist is imparted to the yarn bydirect frictional contact with rotating surfaces, for example as shownin the apparatus of Tully `U.S. Patent No. 2,923,121, or by passing theyarn between two moving surfaces, for example as described in publishedBritish specification No. 821,460. With such `friction twisters,considerably higher rotational speeds can be imparted to the yarn perunit time than with the aforementioned rotating false twisting tubes orspindles.

However, the friction twisters presently available frequently permit aconsiderable amount of slippage of the yarn between the differentworking stations of a false twisting machine and also within one and thesame working station. As a result, there is often a considerablevariation in the number of twists per unit length imparted to the yarn.This of course produces irregularities in the crimped yarn which are notacceptable from a commercial standpoint. `In many instances the yarn iscontacted only on opposed sides by the moving friction surfaces, or isnot in substantially complete frictional contact about its periphery. lnother friction twisters where the yarn is contacted on three or moresides the moving `or rotating `friction surfaces are very rigid ascompared with the yarn, and as a result of this rigidity the yarn isoften damaged substantially through abrasion and there is breakage ofthe yarn filaments, and indeed often the yarn itself is broken.

lt is a primary object of the present invention to eliminate thedisadvantages of the friction twisters presently available, and toprovide a friction twister in which the frictional contact between theyarn and the friction body is suliicient to impart highly etiicientrotation to the yarn with as little slippage as possible, -while at thesame time providing an apparatus in which the frictional losses of theyarn passing through -are so small as to avoid breakage of even theindividual filaments of the yarn.

The `apparatus of the present invention is adapted primarily for `falsetwisting synthetic textile yarns, for example, polyamide yarns ofpoly-hexamethyleneadipamide, or polymers of E-caprolactam orll-aminoundecanoie acid, or polyester yarns, for example, polyethylene-3,103,097 Patented Sept 10, 1963 ice glycol teraphthlate, as well aspolyvinyl yarns, for instance, poly-acrylonitrile.

-In its broadest aspect, the false twisting device of the presentinvention comprises a driven endless belt so arranged on at least threerollers, at least one of which is driven, that at least three beltcourses intersect to define a channel with .at least three sides, eachconsisting of one of the belt courses, through whichthe yarn passes infrictional contact with said belt courses. The aforementioned channel issubstantially normal to the axes of the belt courses which `define it.The endless belt, or a plurality of such belts, is of course .soarranged on said rollers as to impart unidirectional rotation to theyarn passing through the channel defined by the intersecting courses.The belt courses defining the channel thus impart a unidirectionaltorque to the moving yarn by reason of the higher coefficient offriction of the belt as compared with that of the yarn.

ln one embodiment of the present apparatus, three rollers are employedand` -they are arranged in triangular relationship. Accordingly, wherethe three or more belt courses intersect between the three rollers they-arn channel thus defined is of triangular cross-section, when viewedfrom one end. The rollers are so arranged or the intersecting beltcourses are so yguided that the diameter of the circle which can beinscribed in the triangular channel is substantially equ-al to that ofthe yarn being false twisted. The yarn passing through the channel isthus in contact with at least three moving belt courses. `In apreyfeared embodiment the intersecting belt courses defining the channelcomprise the sides of an equilateral triangle, so that the yarn is inuniform frictional contact with the belts. i,

Adjustable guide -means are preferably provided for contacting theintersecting belt courses and for displacing said courses to control thecross-sectional ldimensions fof the yarn passage channel, to therebypermit easy threading of the apparatus and also to enable the yfalsetwisting of Ivarious size yarns. The adjustable guide means also serveto control the amount of pressure applied to the yarn by theintersecting belt courses as the yarn passes through the channel, thusserving to prevent the application of excessive frictional forces uponthe yarn.

Having thus described the apparatus of the present invention in generalterms, there will now be described in detail a preferred embodiment ofthe present invention as shown in the accompanying drawings, whereinFIG. 1 is an elevation of the apparatus, and FIG. 2 is a plan of thesame apparatus as viewed in the direction indicated by the arrows of theline 2-2 of FIG. yl.

Referring now to the drawings, it will be noted that the device includesa support member or plate 1, illustrated as having a circularconfiguration, which is arranged in the complete yarn treating machinebetween yarn feeding means and a yarn take-up device, neither of whichare illustrated. As shown in FIG. 2 the support plate 1, or the means atits center, is provided with a central opening 1a for passage of theyarn Y. Three rollers 2, 3 and 4, of the same diameter are rotatablymounted on hubs 2a, 3a and 4a, respectively, on the same side of supportmember 1, with the respective axes of the rollers positioned relativeone to the other as the apices of an equilateral triangle. Theperipheral edge of each of the rollers is provided with a plurality ofannular grooves 6 of equal size arranged one alongside the other atequally spaced intervals, which serve to receive one or a plurality ofendless belts, which are preferably of a curvilinear cross-section andcorresponding to the configuration of grooves 6.

In the embodiment illustrated, five endless belts, 7-11 are employed.They are of circular or oval cross-section, and consist of elasticmaterial having a high coefficient of friction, preferably with a wire`or coil spring core to somewhat restrict their elasticity and improvetheir wearing qualities.

The roller 2 is positively driven by means not shown and rollers 3 and 4are driven by the endless belts. Belt 7 is threaded about driven roller2 and idler roller 3, while the latter is joined to roller 4 by means ofbelt 8. Belt 9 joins rollers 2 and 4. Belt 1G` parallels belt 7 joiningrollers 2 and 3 and belt 11, like belt 8, is threaded about rollers 3and 4. If desired, another belt might parallel belt 9 in the emptyinnermost grooves of rollers 2 and 4.

The diameter of the endless belts and the dimensions and spacing of thegrooves 6 of the rollers are so chosen andV arranged that the inner beltcourses, three of which are illustrated in FIG. 1,'namely, 7, 8 and 9,intersect between the three rollers. The inner belt courses in anormaltaut position will of course intersect with their respective axespassing through the central axis O (FIG. l) of the support plate 1 sincethe rollers are arranged in equilateral triangular relationship.However, the inner belt courses are so guided, as shown in FIG. l, thatin operation of the device they intersect so as to define a channel forpassage of the yarn Y normally of the belt courses, which intersectionaffords the channel a triangular cross-sectional'configuration, theinscribed circle of which is adapted to the cross-section of the yarn tobe false twisted. In operation the yarn is guided along the axis O ofthe central opening 1a of .the supporting plate 1 thence through thechannel `def-ined by the intersecting belt courses. The yarn is advancedat a predetermined speed and within the channel is in frictional contactwith the intersecting belt courses. The belts are all driven at apredetermined speed and exert a corresponding unidirectional rotation ortorque upon the yarn.

In the apparatus illustrated there is provided a simple adjustable guidemeans for displacing .the intersecting belt courses to Vary thedimensions of |the yarn channel. The guide means consists of a disc 12with a hollow cyclindrical extension 13 which passes through supportingplate 1 and is secured thereto by locking means indicated at 14. Thedisc 12 is freely rotatable and supported about the axis O of thesupport plate. The central opening 1a in support plate 1 is in fact thechannel through the center of cylindrical extension 13 of the disc 12 asshown in FIG. 2. The central opening 1a has been described as in thesupport plate 1 for the reason .that guiding means other than thoseillustrated in the drawing may obviously be employed, but in any event acentral opening 1a between the rollers must be provided for passage ofthe yarn.

Returning to the guiding means illustrated, it will be observed thatthree axially projecting pins 16', 17 and 18, which are preferablyrotatable, are mounted upon rotatable disc 12. These pins cooperate withthe intersecting belt courses in such a manner that upon rotation of thedisc 12 in a counter-clockwise direction, as viewed in FIG. 1, theintersecting belt courses are displaced in such a manner as to widen orgreatly increase the internal dimensions or area of the yarn channel.

The disc 12 is rotated by means of a lever arm 19 mounted thereon, whichcan be locked in different positions to impart different degrees ofrotation to the disc 12 with respect to the support plate 1 and rollers2, 3 and 4. Locking means are provided at the outer end of lever arm 19,which consists of a clamping member 21, a projection of which engagesthe edge of the support plate 1, and which can be clamped fast withrespect to thel supporting plate by means of a screw 22 which extendsthrough Ithe lever arm 19 and is seated in the threaded bore of theclamping member 21. Upon loosening ofthe screw 22, the lever arm 19 andthus the rotatable disc 12 can be adjusted as necessary and then lockedin the proper position by retightening screw 22. j

In the position shown in FIG. l, as indicated by the solid linesdefining projecting guide pins 16, 17 and 18, the adjustable guide meansis in operating position. The axis of set screw 22 is at point X1 andwith the disc 12 in this position the guide pins deflect theintersecting belts silghtly; guide pin 16 presses against belt 9, pin 17against belts 7 and 1t) and guide pin 18 against belts 8 and 11. In thisposition the intersecting belt courses pass tangentially to the movingtextile yarn Y so that rotation is imparted to the yarn, but thepressure of frictional contact between the belts, which are 'themselvesflexible, and the yarn is not sufficient to abrade or in fact in any waydegrade or adversely affect the moving yarn.

In order to introduce the textile yarn into the yarn channel formed bythe intersecting belt courses, the disc 12 is rotated by means of thelever arm 19 through the angle A so that the axis of the set screw 22 islocated at the point X2, for example. The guide pins 16, 17 and 18 thenassume the position shown by their dotted outlines in FIG. l and in thisposition deflect the intersecting belt courses so that at the pointwhere they cross there is produced a much larger yarn channel, asindicated by the dotted line belt courses. In this position the textileyarn can easily be threaded through the larger triangular channel.Thereupon the disc 12 is again brought into operating position and theset screw 22 secured at position X1.

In the apparatus illustrated and described five endless belts have beenemployed, and tests with the device have proved its effectiveness andflexibility. Yarn rotational speeds of one million revolutions perminute have been achieved Without yarn breakage. It is not essentialthat five belts be employed, and good results have been o-btained withfour, six and even three belts. It is essential only that there be atleast three belt courses intersecting to define the yarn channel, asshown in FIG. 1. On the other hand, the apparatus illustrated may beoperated with but one long endless belt which is threaded over therollers so as to provide at least three intersecting courses o-r, forexample, to provide five such courses replacing the five individualbelts illustrated and described.

From the labove it will be appreciated that the apparatus of the presentinvention is considerably more flexible than one employing comparativelyrigid friction surfaces, which may be spaced about the moving yarn as inTully U.S. Patent No. 2,923,121, for example. In the present apparatusthe degree of frictional contact between each of the flexible belts andthe moving yarn can easily be controlled by adjustment of the yarnguiding means, and yarns of widely diverse cross-section can beprocessed.

While a preferred embodiment of the present invention has been describedin detail it is obvious that many modifications may be made to thedevice without departing from the spirit and scope of this invention asset forth in the appended claims. It is only essential that theapparatus provide at least three intersecting belt courses which definea yarn channel wherein unidirectional torque is imparted to the yarn.Clearly the three rollers illustrated might be arranged in a triangularrelationship which is not an equilateral triangle. Likewise, four ormore rollers might be employed so as to permit the belt courses tointersect and contact the yarn from more than three sides.

We claim:

l. Apparatus for false twisting textile yarns comprising at least onedriven endless flexible belt, having a high coefhcient of friction ascompared with that of the yarn to be false twisted, so arranged on atleast three spaced rollers that at least three belt courses intersectintermediate said rollers to define a channel for passage of the yarnsubstantially normal to the belt courses adjacent said channel, saidbelt further being so Iarranged on said rollers as to impartunidirectional rotary movement to yarn passing through said channel andin contact with the intersecting belt courses, and guide means soarranged as to contact and displace the belt courses deiining saidchannel to thereby vary the internal dimensions of the channel.

2. Apparatus for false twisting textile yarns comprising at least oneendless flexible belt, having a curvilinear crossfsection and a highcoeliicient of friction as compared with that of the yarn to be falsetwisted, so arranged on at least three spaced rollers, at least one ofwhich is driven, that at least three belt courses intersect intermediatesaid rollers, adjustable guide means so arranged as to contact anddisplace the intersecting belt courses to define a channel for passageof the yarn substantially normal to the intersecting belt courses, saidchannel as viewed from one end having at least three sides, the degreeof displacement of said intersecting belt courses defining the area ofsaid channel, said intersecting belt courses being so arranged on saidrollers as to impart unidirectional rotary movement to yarn passingthrough said channel land in contact with said courses therein.

3. Apparatus as set forth in claim 2 wherein the rollers upon which theintersecting belt courses are arranged are such that the speeds of thebelt courses deli-ning the yarn channel are substantially equal.

4. Apparatus for false twisting textile yarns comprising three rotatablerollers mounted in triangular relationship, at least one of said rollersbeing driven, at least one endless iiexible belt, having a highcoeiiicient of `friction as compared with that of the yarn to be falsetwisted, so arranged on said rollers that `at least three belt coursesintersect intermediate the rollers to deiine a channel of triangularcross-section, as viewed from one end, for passage of the yarntherethrough substantially normal `to and in contact with theintersecting belt courses, and guide means so larranged as to contactand displace at least one belt course defining said channel to therebyvary the cross-sectional area of said channel.

5. Apparatus as set forth in claim 4 wherein one of the three rollers isdriven and at least three endless belts are employed, one from thedriven roller to each of the other rollers and one between said otherrollers.

6. Apparatus for false twisting textile yarns comprising three rollers,at least one of which is driven, rotatably mounted at the apices of anequilateral triangle, at least one endless flexible belt, having a highcoeiiicient of fricbelt courses would normally intersect, with the taxisotV each passing through the center of the triangle, adjustable guidemeans so arranged as to Contact and. displace said belt courses todefine a triangular channel for passage of the yarn substantially normalto the belt courses.

7. Apparatus as set forth in claim 6 wherein the belt courses whichintersect are so arranged on the three rollers as to impartunidirectional rotary movement to yarn passing through the triangularchannel.

8. Apparatus for false twisting textile yarns comprising three rollers,at least one of which is driven, rotatably mounted at the apices of `asubstantially equilateral triangle, at least one endless flexible belt,having a high coefficient of :friction as compared with that of the yarnto be false twisted, so arranged on said rollers that at `least threebelt courses would normally intersect with the axis of each passingthrough the center of the triangle, `at least three adjustable guides,one in contact with each of the intersecting belt courses, mounted lforsimultaneous arcuate displacement with respect to the normalintersection of said belt courses to thereby deflect said courses anddefine a triangular channel for passage of the yarn substantially normalto the belt courses, and means for so displacing said guides as to varythe cross-sectional dimensions of said triangular channel.

9. Apparatus as iset 'forth in claim S wherein one of the three rollersis driven and at least three endless ilem'ble belts are employed, onefrom the driven roller to each of the other rollers Iand one betweensaid other rollers,

. with the belts so arranged as to impart unidirectional rotary movementto yarn passing through the triangular channel.

References Cited in the tile of this patent UNITED STATES PATENTSHammond et yal. May 22, 1962

1. APPARATUS FOR FALSE TWISTING TEXTILE YARNS COMPRISING AT LEAST ONEDRIVEN ENDLESS FLEXIBLE BELT, HAVING A HIGH COEFFICIENT OF FRICTION ASCOMPARED WITH THAT OF THE YARN TO BE FALSE TWISTED, SO ARRANGED ON ATLEAST THREE SPACED ROLLERS THAT AT LEAST THREE BELT COURSES INTERSECTINTERMEDIATE SAID ROLLERS TO DEFINE A CHANNEL FOR PASSAGE OF THE YARNSUBSTANTIALLY NORMAL TO THE BELT COURSES ADJACENT SAID CHANNEL, SAIDBELT FURTHER BEING SO ARRANGED ON SAID ROLLERS AS TO IMPARTUNIDIRECTIONAL ROTARY MOVEMENT TO YARN PASSING THROUGH SAID CHANNEL ANDIN CONTACT WITH THE INTERSECTING BELT COURSES, AND GUIDE MEANS SOARRANGED AS TO CONTACT AND DISPLACE THE BELT COURSES DEFINING SAIDCHANNEL TO THEREBY VARY THE INTERNAL DIMENSIONS OF THE CHANNEL.